Purpose of study: Hepatocellular carcinoma (HCC) is the third leading cause of cancer death. Although sorafenib has been shown to improve survival of patients with advanced HCC, this improvement is modest and patients eventually have refractory disease. The purpose of this study is to assess the anti-tumor and anti-angiogenic activities of foretinib, a vascular endothelial growth factor receptor 2 (VEGFR-2) and c-Met inhibitor using mouse models of human HCC.
Experimental techniques: SK-HEP1 and 21-0208 HCC cells as well as patient-derived HCC models were employed to study the anti-tumor and antiangiogenic activities of foretinib. Changes of biomarkers relevant to hepatocyte growth factor (HGF) signaling pathways were determined by Western blotting. Microvessel density, apoptosis and cell proliferation were analyzed by immunohistochemistry.
Results: Treatment of SK-HEP1 cells with foretinib resulted in growth inhibition, G2/M cell cycle arrest, reduced colony formation and blockade of HGF-induced cell migration. In both orthotopic and ectopic models of HCC, foretinib potently inhibited tumor growth in a dose-dependent manner. Inhibition of angiogenesis correlated with inactivation of VEGFR-2/c-Met signaling pathways. Foretinib also caused elevation of p27 and Bim but reduced cyclin B1 expression and p-c-Myc, which resulted in a reduction in cellular proliferation and the induction of tumor cell apoptosis. In an orthotopic model, foretinib potently inhibited primary tumor growth and significantly prolonged mouse survival.
Data interpretations: Foretinib demonstrated significant antitumor activities in patient-derived HCC xenograft models. This study provides a compelling rationale for clinical investigation in patients with advanced HCC.